1. Field of the Invention
This invention relates generally to an adsorbent and/or catalyst particle that has improved adsorbent properties and/or improved or newly existing catalytic properties by the use of the particle in combination with a particular binder to produce a particle/binder system. The binder can either cross-link to the particle, cross-link to itself and envelope the particle or both.
2. Background Art
Oxides of metals and certain non-metals are known to be useful for removing constituents from a gas or liquid stream by adsorbent mechanisms. For example, the use of activated alumina is considered to be an economical method for treating water for the removal of a variety of pollutants, gasses, and some liquids. Its highly porous structure allows for preferential adsorptive capacity for moisture and contaminants contained in gasses and some liquids. It is useful as a desiccant for gasses and vapors in the petroleum industry, and has also been used as a catalyst or catalyst-carrier in chromatography and in water purification. Removal of contaminants such as phosphates by activated alumina are known in the art. See, for example, Yee, W., xe2x80x9cSelective Removal of Mixed Phosphates by Activated Alumina,xe2x80x9d J.Amer. Waterworks Assoc., Vol. 58, pp. 239-247 (1966).
U.S. Pat. No. 5,366,948 to Absil et al. discloses the preparation of a fluid cracking catalyst. The catalyst was prepared by the addition of phosphoric acid to a zeolite slurry. A second slurry was prepared by mixing colloidal silica with a source of alumina which is acid soluble. This slurry was mixed with a clay, then the zeolite slurry was added. The final slurry was spray dried at an outlet temperature of 350-360xc2x0 F. and a pH of 2.8, then calcined in air at approximately 1000xc2x0 F. The cracking catalyst was used to produce high octane gasoline, and increased lower olefins, especially propylene and butylene.
U.S. Pat. No. 5,422,323 to Banerjee et al. discloses the preparation of a pumpable refractory insulator composition. The composition consists of the combination of a wet component of colloidal silica (40%) in water, and a dry component consisting of standard refractory material. Examples of refractory material include clay, kaolinite, mullite, alumina and alumina silicates. The resulting insulating composition was cast into shape, dried and baked to form an insulating layer.
Japanese Patent No. 63264125 to Fumikazu et al. discloses the preparation of dry dehumidifying materials. Moisture is removed from room air or gas as it passes through a dehumidifying rotor of zeolite (70% by weight) and an inorganic binder (2-30% by weight). The inorganic binder includes colloidal silica, colloidal alumina, silicates, aluminates and bentonite. Wet air was passed through the dehumidifying rotor, and the amount of dried air was assessed.
Japanese Patent No. 60141680 to Kanbe et al. discloses the preparation of a refractory lining repair material. The material was prepared by adding a solution of phosphoric acid with ultra fine silica powder to a mixture of refractory clay and refractory aggregates composed of grog, alumina, silica, zircon and pyrophyllite. The refractory material has improved bonding strength and minute structure, and are useful for molten metal vessels such as ladles, tundishes, and electric furnaces.
Adsorbent particles of the prior art have not achieved the ability to remove particular contaminants from a liquid or gas stream, such as, for example, a waste stream or drinking water, to acceptably low levels. Additionally, the adsorbent particles of the prior art have not been able to bind tightly to particular contaminants so that the adsorbent particle/contaminant composition can be safely disposed of in a landfill. Thus, there has been a need in the art for adsorbents that have improved ability to adsorb particular materials, particularly contaminants from a gas or liquid stream, to thereby purify the stream. There has been a need in the art for the adsorbent particles to tightly bind to the adsorbed contaminant. Also, there has been a need in the art for catalysts that have the ability or that have an improved ability to catalyze the reaction of contaminants into non-contaminant by-products.
Typically in the art, binders block active sites on the adsorbent and catalyst particles, thereby reducing the efficiency of such particles. Therefore, there is a need in the art for a binder system that binds adsorbent and/or catalytic particles together without reducing the performance of the particles.
Applicants have discovered that by using a special binder for adsorbent and/or catalytic particles, improved or new adsorbent and/or catalytic properties can be achieved.
None of the above-cited documents discloses the compositions or processes such as those described and claimed herein.
In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a method for producing an adsorbent and/or catalyst and binder system comprising
i) mixing components comprising
a) a binder comprising a colloidal metal oxide or colloidal metalloid oxide,
b) an oxide adsorbent and/or catalyst particle, and
c) an acid,
ii) removing a sufficient amount of water from the mixture to cross-link components a and b to form an adsorbent and/or catalyst and binder system.
In another aspect, the invention provides for an adsorbent and/or catalyst system made by the processes of the invention.
In one aspect, the invention provides an adsorbent and/or catalyst and binder system comprising a binder that has been cross-linked with at least one type of oxide adsorbent and/or catalyst particle.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a liquid or gas stream comprising contacting the adsorbent and/or catalyst binder system with the contaminant in the stream for a sufficient time to reduce or eliminate the amount of contaminant from the stream.
In yet another aspect, the invention provides a method for catalyzing the degradation of an organic compound comprising contacting the organic compound with the adsorbent and/or catalyst system for a sufficient time to catalyze the degradation of an organic compound.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a gas stream by catalysis comprising contacting the adsorbent and/or catalyst binder system with a gas stream containing a contaminant comprising an oxide of nitrogen, an oxide of sulfur, carbon monoxide, hydrogen sulfide, or mixtures thereof for a sufficient time to reduce or eliminate the contaminant amount.
In yet another aspect, the invention provides a method for producing an adsorbent and/or catalyst and binder system comprising
i) mixing components comprising
a) a binder comprising a colloidal metal oxide or colloidal metalloid oxide,
b) a first adsorbent and/or catalyst particle that does not cross-link with the binder, and
c) an acid,
ii) removing a sufficient amount of water from the mixture to cross-link component a to itself, thereby entrapping and holding component b within the cross-linked binder, to form an adsorbent and/or catalyst and binder system.
In another aspect the invention relates to a composition for binding adsorbent and/or catalytic particles to produce an agglomerated particle comprising (a) a colloidal metal oxide or colloidal metalloid oxide and (b) an acid.
In another aspect the invention relates to a kit for binding adsorbent and/or catalytic particles to produce an agglomerated particle comprising (a) a colloidal metal oxide or colloidal metalloid oxide and (b) an acid.
In yet another aspect, the invention provides a method for binding adsorbent and/or catalytic particles, comprising the steps of:
(a) mixing colloidal alumina or colloidal silica with the particles and an acid;
(b) agitating the mixture to homogeneity; and
(c) heating the mixture for a sufficient time to cause cross-linking of the aluminum oxide in the mixture.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the Examples included therein.
Before the present compositions of matter and methods are disclosed and described, it is to be understood that this invention is not limited to specific synthetic methods or to particular formulations, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
The singular forms xe2x80x9ca,xe2x80x9d xe2x80x9canxe2x80x9d and xe2x80x9cthexe2x80x9d include plural referents unless the context clearly dictates otherwise.
The term xe2x80x9cparticlexe2x80x9d as used herein is used interchangeably throughout to mean a particle in the singular sense or a combination of smaller particles that are grouped together into a larger particle, such as an agglomeration of particles.
The term xe2x80x9cppmxe2x80x9d refers to parts per million and the term xe2x80x9cppbxe2x80x9d refers to parts per billion.
The term xe2x80x9cand/orxe2x80x9d in xe2x80x9cadsorbent and/or catalystxe2x80x9d refers to a particle that either acts as a catalyst, or can act as both an adsorbent or catalyst under different circumstances due to, for example, the positive composition and the type of contaminant.
This invention, in one aspect, relates to a method for producing an adsorbent and/or catalyst and binder system comprising
i) mixing components comprising
a) a binder comprising a colloidal metal oxide or colloidal metalloid oxide,
b) an oxide adsorbent and/or catalyst particle, and
c) an acid,
ii) removing a sufficient amount of water from the mixture to cross-link components a and b to form an adsorbent and/or catalyst and binder system.
In another aspect, the invention provides for an adsorbent and/or catalyst system made by the processes of the invention.
In one aspect, the invention provides an adsorbent and/or catalyst and binder system comprising a binder that has been cross-linked with at least one type of oxide adsorbent and/or catalyst particle.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a liquid or gas stream comprising contacting the adsorbent and/or catalyst binder system with the contaminant in the stream for a sufficient time to reduce or eliminate the amount of contaminant from the stream.
In yet another aspect, the invention provides a method for catalyzing the degradation of an organic compound comprising contacting the organic compound with the adsorbent and/or catalyst system for a sufficient time to catalyze the degradation of an organic compound.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a gas stream by catalysis comprising contacting the adsorbent and/or catalyst binder system with a gas stream containing a contaminant comprising an oxide of nitrogen, an oxide of sulfur, carbon monoxide, hydrogen sulfide, or mixtures thereof for a sufficient time to reduce or eliminate the contaminant amount.
In yet another aspect, the invention provides a method for producing an adsorbent and/or catalyst and binder system comprising
i) mixing components comprising
a) a binder comprising a colloidal metal oxide or colloidal metalloid oxide,
b) a first adsorbent and/or catalyst particle that does not cross-link with the binder, and
c) an acid,
ii) removing a sufficient amount of water from the mixture to cross-link component a to itself, thereby entrapping and holding component b within the cross-linked binder, to form an adsorbent and/or catalyst and binder system.
In another aspect the invention relates to a composition for binding adsorbent and/or catalytic particles to produce an agglomerated particle comprising (a) a colloidal metal oxide or colloidal metalloid oxide and (b) an acid.
In another aspect the invention relates to a kit for binding adsorbent and/or catalytic particles to produce an agglomerated particle comprising (a) a colloidal metal oxide or colloidal metalloid oxide and (b) an acid.
In yet another aspect, the invention provides a method for binding adsorbent and/or catalytic particles, comprising the steps of:
(a) mixing colloidal alumina or colloidal silica with the particles and an acid;
(b) agitating the mixture to homogeneity; and
(c) heating the mixture for a sufficient time to cause cross-linking of the aluminum oxide in the mixture.
When the system acts as an adsorbent, the adsorbent and binder system of this invention has improved or enhanced adsorptive features. In one embodiment, the system of this invention can adsorb a larger amount of adsorbate per unit volume or weight of adsorbent particles than a prior art system. In another embodiment, the adsorbent and binder system of this invention can reduce the concentration of contaminants or adsorbate material in a stream to a lower absolute value than is possible with a non-bound or prior art-bound particle. In particular embodiments, the adsorbent and binder system of this invention can reduce the contaminant concentration in a stream to below detectable levels. Adsorption is a term well known in the art and should be distinguished from absorption. The adsorbent particles of this invention chemically bond to and very tightly retain the adsorbate material. These chemical bonds are ionic and/or covalent in nature.
The catalyst and binder system of the invention can also be used for the catalytic decomposition or remediation of contaminants. The catalyst system achieves improved catalytic performance or catalytic properties never seen before for a particular contaminant. The adsorbent and/or catalyst and binder system can be prepared by techniques set forth below to form a multifunctional composite particle. The catalysis can be at room temperature for certain applications.
The binder comprises an oxide particle that can react, preferably cross-link, with the other oxide complexes. This binder can also react, preferably cross-link, with itself. The binder forms cross-links with other oxide complexes upon drying by forming chemical bonds with itself and with other oxides. Under acidic conditions, the binder has a large number of surface hydroxyl groups. In one embodiment, the binder, which is designated as Bxe2x80x94OH, cross-links with itself upon the loss of water to generate Bxe2x80x94Oxe2x80x94B. In addition cross-linking with itself, the binder Bxe2x80x94OH can also cross-link with an adsorbent and/or catalyst oxide complex (Mxe2x80x94O) or hydroxyl complex (Mxe2x80x94OH) to produce Bxe2x80x94Oxe2x80x94M. The resulting binder system consists of a three dimensional network or matrix wherein the component particles are bound together with Bxe2x80x94Oxe2x80x94B and Bxe2x80x94Oxe2x80x94M bonds. The resulting system can be used as an adsorbent and/or catalyst system. The resultant system is sometimes referred to as an agglomerated particle.
xe2x80x9cColloidal metal or metalloid oxide (i.e. colloidal metal oxide or colloidal metalloid oxide) binderxe2x80x9d as defined herein means a particle comprising a metal or metalloid mixed hydroxide, hydroxide oxide or oxide particle, such that the weight loss from the colloidal metal or metalloid oxide binder due to loss of water upon ignition is from 1 to 100%, 5 to 99%, 10 to 98%, or 50 to 95% of the theoretical water weight loss on going from the pure metal or metalloid hydroxide to the corresponding pure metal or metalloid oxide. The loss of water on going from the pure metal or metalloid hydroxide to the corresponding pure metal or metalloid oxide (e.g. the conversion of n M(OH)x to MnOm and y H2O or more specifically from 2 Al(OH)3 to Al2O3 and 3 H2O) is defined as 100% of the water weight loss. Thus, the weight loss refers to loss of water based on the initial weight of water (not the total initial binder weight). There is a continuum of metal or metalloid hydroxides, hydroxide oxides, and oxides in a typical commercial product, such that, loss or removal of water from the metal or metalloid hydroxides produces the corresponding hydroxide oxides which upon further loss or removal of water give the corresponding metal or metalloid oxides. Through this continuum the loss or removal of water produces Mxe2x80x94Oxe2x80x94M bonds, where M is a metal or metalloid. The particles of this continuum, except for the pure metal or metalloid oxides, are suitable to serve as colloidal metal or colloidal oxide binders in this invention.
In another embodiment, the binder system involves the use of a binder in combination with a particle with few or no surface hydroxyl groups, such that the particle does not cross-link or only nominally cross-links with the binder. Examples of particles that posses only nominal amounts or that do not posses surface hydroxyl groups include particles of metals, such as, but not limited to tin or zinc, or carbon. In another embodiment, component b does not contain an oxide particle. Metal alloys such as bronze can also be used. In a preferred embodiment, the particle is activated carbon. In this embodiment, the binder cross-links with itself in a manner described above to form a three dimensional network or matrix that physically entraps or holds component b without cross-linking or cross-linking only to a very small degree with component b. The resulting binder system can be used as an adsorbent and/or catalyst system.
In another embodiment, the invention is directed to a method for producing an adsorbent and/or catalyst and binder system comprising
i) mixing components comprising
a) a binder comprising a colloidal metal oxide or colloidal metalloid oxide,
b) a first adsorbent and/or catalyst particle that does not cross-link with the binder, and
c) an acid,
ii) removing a sufficient amount of water from the mixture to cross-link component a to itself, thereby entrapping and holding component b within the cross-linked binder, to form an adsorbent and/or catalyst and binder system,
further comprising a second adsorbent and/or catalyst particle that cross-links with the binder, thereby cross-linking the binder and the second particle and thereby entrapping and holding the first particle within the cross-linked binder and/or within the cross-linked binder and second particle. In this embodiment, the system comprises a binder and oxide adsorbent and/or catalyst particles that cross-links with the binder as well as particles that have a limited amount of surface hydroxyl groups, which do not cross-link with the binder. In this case, the binder cross links to itself and to the oxide complex particles, and the binder also forms a network or matrix around the particles that have a limited number of surface hydroxyl groups.
Binders that can be used in the present invention are colloidal metal or metalloid oxide complexes. Colloidal as used herein is defined as an oxide group that has a substantial number of hydroxyl groups that can form a dispersion in aqueous media. This is to be distinguished from the other use of the term colloid as used in regard to a size of less than 1 xcexcm. The binders herein are typically small in size, e.g. less than 150 xcexcm, but they do not have to be all less than 1 xcexcm. Typically, the binder is un-calcined to maximize the hydroxyl group availability. Moreover, they must have a substantial number of hydroxyl groups that can form a dispersion in aqueous media, which is not always true of colloid particles merely defined as being less than 1 xcexcm. Examples of binders include but are not limited to any metal or metalloid oxide complex that has a substantial number of hydroxyl groups that can form a dispersion in aqueous media. In one embodiment, the binder is colloidal alumina, colloidal silica, colloidal metal oxide where the metal is iron, or a mixture thereof, preferably colloidal alumina or colloidal silica. Colloidal alumina can be a powder, sol, gel or aqueous dispersion. Colloidal alumina may be further stabilized with an acid, preferably nitric acid, and even more preferably 3 to 4% nitric acid. In a preferred embodiment, the colloidal alumina is un-calcined with a sufficient number of hydroxyl groups such that the total particle weight loss (as distinguished from just water weight loss discussed above) upon ignition is between from 5% to 34%, more preferably from 20% to 31%. The colloidal alumina size is preferably from 5 nm to 400 xcexcm, preferably at least 30 wt % is less than 25 xcexcm and 95 wt % is less than 100 xcexcm. The colloidal silica is preferably un-calcined with a sufficient number of hydroxyl groups such that the total particle weight loss upon ignition is between from 5% to 37%, more preferably from 20% to 31%. The colloidal silica size is preferably from 5 nm to 250 xcexcm, preferably at least 30 wt % is less than 25 xcexcm and 95 wt % is less than 100 xcexcm. In one embodiment, the binder is from 1% to 99.9% by weight of the mixture, preferably from 10% to 35% by weight. As used herein, the binder will be referred to as xe2x80x9ccolloidalxe2x80x9d to distinguish it from particle b, as the composition types can be the same, e.g. both can contain aluminum oxides.
Although prior art binders can be used in combination with the binder system of the present invention, these prior art binders lack certain advantages. In the present invention, the activity is not degraded when exposed to aqueous solutions. The system is also very durable and not subject to falling apart when exposed to a waste stream, unlike other prior art adsorbent and/or catalyst and binder systems, such as polyvinyl pyrolidone, starch, or cellulose.
The invention contemplates the use of any prior art oxide adsorbent and/or catalyst particle or composite particle of two or more types of particles and binder system, but replacing the prior art binder with the binder of the present invention. In one aspect, the invention provides an adsorbent and/or catalyst and binder system comprising a binder that has been cross-linked with at least one type of oxide adsorbent and/or catalyst particles. In one embodiment, component b comprises at least two different types of oxide adsorbent and/or catalyst particles, to form a cross-linking between the binder and both particles to thereby form a composite particle.. In another embodiment, component b comprises at least three different types of adsorbent and/or catalyst particles. In a preferred embodiment, component b comprises an oxide particle, preferably a metal oxide particle, and even more preferably a non-ceramic, porous metal oxide particle. Examples of such particles include, but are not limited to, oxide complexes, such as transition metal oxides, lanthanide oxides, thorium oxide, as well as oxides of Group IIA (Mg, Ca, Sr, Ba), Group IIIA (B, Al, Ga, In, Tl), Group IVA (Si,Ge, Sn, Pb), and Group VA (As, Sb, Bi). In general, any oxide complex that is a basic anhydride is suitable for component b. In another embodiment, component b comprises an oxide of aluminum, titanium, copper, vanadium, silicon, manganese, iron, zinc, zirconium, tungsten, rhenium, arsenic, magnesium, thorium, silver, cadmium, tin, lead, antimony, ruthenium, osmium, cobalt or nickel or zeolite. Typically, any oxidation state of the oxide complexes may be useful for the present invention. The oxide can be a mixture of at least two metal oxide particles having the same metal with varying stoichiometry and oxidation states. In one embodiment, component b comprises Al2O3, TiO2, CuO, Cu2O, V2O5, SiO2, MnO2, Mn2O3, Mn3O4,ZnO, WO2, WO3, Re2O3, As2O3, As2O5, MgO, ThO2, Ag2O, AgO, CdO, SnO2, PbO, FeO, Fe2O3, Fe3O4, Ru2O3, RuO, OSO4, Sb2O3, CoO, Co2O3, NiO or zeolite. In a further embodiment, component b further comprises a second type of adsorbent and/or catalyst particles of an oxide of aluminum, titanium, copper, vanadium, silicon, manganese, iron, zinc, zirconium, tungsten, rhenium, arsenic, magnesium, thorium, silver, cadmium, tin, lead, antimony, ruthenium, osmium, cobalt or nickel or zeolite, activated carbon, including coal and coconut carbon, peat, zinc or tin. In another embodiment, component b further comprises a second type of adsorbent and/or catalyst particles of aluminum oxide, titanium dioxide, copper oxide, vanadium pentoxide, silicon dioxide, manganese dioxide, iron oxide, zinc oxide, zeolite, activated carbon, peat, zinc or tin particle. Typical zeolites used in the present invention include xe2x80x9cYxe2x80x9d type, xe2x80x9cbetaxe2x80x9d type, mordenite, and ZsM5. In a preferred embodiment, component b comprises non-amorphous, non-ceramic, crystalline, porous, calcined aluminum oxide that was produced by calcining the precursor to the calcined aluminum oxide at a particle temperature of from 400xc2x0 C. to 700xc2x0 C., preferably in the gamma, chi-rho, or eta form. The precursor to calcined aluminum oxide can include but is not limited to boehmite, bauxite, pseudo-boehmite, scale, Al(OH)3 and alumina hydrates. In the case of other metal oxide complexes, these complexes can also be calcined or uncalcined.
The adsorbent and/or catalyst particles used in this invention can be unenhanced or enhanced by processes known in the art or described below. For example, the particles can be dried to be activated or can be of a composition or treated by ion or electron beam or acid activation or enhancement treatment processes disclosed in the prior filed parent applications of and in applicants"" two copending applications filed on the same date as this application and entitled (1) xe2x80x9cEnhanced Adsorbent and Room Temperature Catalyst Particle and Method of Making and Using Therefor,xe2x80x9d which is a continuation-in-part of PCT/US96/05303, filed Apr. 17, 1996, pending, which is a continuation-in-part of U.S. application Ser. No. 08/426,981, filed Apr. 21, 1995, pending, and (2) xe2x80x9cAcid Contacted Enhanced Adsorbent Particle and Method of Making and Using Therefor,xe2x80x9d which is a continuation-in-part of U.S. application Ser. No. 08/662,331, filed Jun. 12, 1996, pending, which is a continuation-in-part of PCT/US95/15829, filed Jun. 12, 1995, pending, which is a continuation-in-part of U.S. application Ser. No. 08/351,600, filed Dec. 7, 1994, abandoned, the disclosures of both applications filed on the same date as this application and all of their prior filed priority applications are herein incorporated by this reference in their entireties for all of their teachings, indirectly, but not limited to particle compositions and methods of treatment.
An acid is required to cross-link the binder with component b. The addition of an acid to the binder facilitates or enables the reaction between the binder and the oxide particle. A strong or dilute acid can be used. A dilute acid is preferred to minimize etching of certain particles. Typically the acid is diluted with water to prevent dissolution of the particle and for cost effectiveness. The acid treatment is preferably of a concentration (i.e. acid strength as measured by, e.g., normality or pH), acid type, temperature and length of time to cross-link the binder and component b.
In one embodiment, the acid comprises nitric acid, sulfuric acid, hydrochloric acid, boric acid, acetic acid, formic acid, phosphoric acid or mixtures thereof, preferably acetic acid or nitric acid. In another embodiment, the concentration of the acid is from 0.15 N to 8.5 N, preferably from 0.5 N to 1.7 N. The volume of dilute acid used must be high enough so that the adsorbent and/or catalyst particle of the present invention can be used as is or further processed, such as extruded or filter pressed.
In order to ensure efficient cross-linking between the binder and the oxide particle component, water is removed from the resulting binder system. This is typically performed by using a drying agent or heating the system. The cross-linking temperature as used herein is the temperature at which cross-linking between the binder and the oxide adsorbent and/or catalyst component b occurs at an acceptable rate or the temperature at which the binder reacts with itself at an acceptable rate. In one embodiment, the cross-linking temperature is from 25xc2x0 C. to 400xc2x0 C. Thus, in one embodiment, the cross-linking temperature for certain binders is at room temperature although the rate of cross-linking at this temperature is slow. In a various embodiments, the cross-linking temperature is from 50xc2x0 C., 70xc2x0 C., 110xc2x0 C., or 150xc2x0 C. to 200xc2x0 C., 250xc2x0 C., 300xc2x0 C., or 150xc2x0 C., preferably 150xc2x0 C. to 300xc2x0 C., even more preferably about 250xc2x0 C. The cross-linking process can take place in open air, under an inert atmosphere or under reduced pressure. The cross-linking temperature can effect the activity of the adsorbent and/or catalyst and binder system. When cross-linking occurs in the open air, then the particle is more susceptible to oxidation as the cross-linking temperature is increased. Oxidation of the particle can ultimately reduce the activity of the particle.
Preferably, during or after step (i), the mixture of step (i) is not heated above the cross-linking temperature of the colloidal metal oxide or colloidal metalloid oxide. Preferably, during or after step (i), the mixture of step (i) is not heated to or above the calcining temperature of the colloidal metal oxide or colloidal metalloid oxide. Preferably, during or after step (i), the mixture of step (i) is not heated to or above the calcining temperature of the particle. In various embodiments, during or after step (i), the mixture of step (i) is not heated above 500xc2x0 C., 450xc2x0 C., 400xc2x0 C., 350xc2x0 C., 300xc2x0 C., or 250xc2x0 C., preferably not above 400xc2x0 C. Cross-linking should be distinguished from calcining. Calcining typically involves heating a particle to remove any residual water that may be on the particle as well as change the lattice structure of the particle to form a crystalline particle. For example for producing a crystalline aluminum oxide particle, the calcining temperature is about 400xc2x0 C. to about 700xc2x0 C. Calcining also removes the hydroxyl groups on the binder that are required for cross-linking. Therefore, heating the system during or after step (i) above the cross-linking temperature into the particle or binder calcining temperature range or above is detrimental to the system. Thus, prior art systems, where mixtures of colloidal alumina and/or colloidal silica are (1) calcined or recalcined or (2) heated to form a refractory material are not a part of this invention.
In another aspect, the invention provides for an adsorbent and/or catalyst system made by the process of the invention.
The binder system of the invention is made in one embodiment by the following general process. The (1) binder and (2) adsorbent and/or catalyst particles are pre-mixed in dry form. The colloidal binder can be added or prepared in situ. For example, alum could be added as a dry powder and converted to colloidal alumina in situe. Other aluminum based compounds can be used for the in situ process, such as aluminum chloride, aluminum secondary butoxide, and the like. A solution of the acid is added to the mixture, and the mixture is stirred or agitated, typically from 1 minute to 2 hours, preferably from 10 minutes to 40 minutes, until the material has a homogeneous xe2x80x9cclayxe2x80x9d like texture. The mixture is then ready for cross-linking or can be first fed through an extruder and then cut or chopped into a final shape, preferably spheres, pellets or saddles, typically of a size from 0.2 mm to 3 mm, preferably 0.5 to 1.5 mm. After the final shape is made, the product is transferred to a drying oven where they are dried from 15 minutes to 4 hours, preferably from 30 minutes to 2 hours. Once the binder is added to the adsorbent and/or catalyst particles (component b), the mixture is not heated to calcine or recalcine the particle b or binder. Such calcining or recalcining would detrimentally change the surface characteristics of component b by closing up the micropores. Additionally, the particles of the invention are preferably not sintered, as this would detrimentally affect the micropores by closing up the micropores and would detrimentally decrease the pore volume and surface area. The particles and binder system are also not heated above the calcining temperature to form a refractory material. Any other process that would increase the size or eliminate micropores, enlarge the size of, create macropores at the expense of micropores or destroy macropores, or would decrease the surface area available for adsorption or catalysis should preferably be avoided.
The size and shape of the particles used in this invention prior to extruding can vary greatly depending on the end use. Typically, for adsorption or catalytic applications, a small particle size such as 5 xcexcm or greater to about 250 xcexcm are preferable because they provide a larger surface area than large particles.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a liquid or gas stream comprising contacting the adsorbent and/or catalyst binder system with the contaminant in the stream for a sufficient time to reduce or eliminate the amount of contaminant from the stream. In one embodiment, the stream is a liquid, preferably water. In another embodiment, the stream is a gas, preferably comprising air or natural gas.
The adsorbent and/or catalyst binder system of this invention can be used for environmental remediation applications. In this embodiment, contaminants from a liquid or gas stream can be reduced or eliminated by a catalysis reaction. In another embodiment, contaminants from a liquid or gas stream can be reduced or eliminated by an adsorption reaction. The particle can be used to remove contaminants, such as, but not limited to, heavy metals, organics, including hydrocarbons, chlorinated organics, including chlorinated hydrocarbons, inorganics, or mixtures thereof. Specific examples of contaminants include, but are not limited to, acetone, ammonia, benzene, carbon monoxide, chlorine, hydrogen sulfide, trichloroethylene, 1,4-dioxane, ethanol, ethylene, formaldehyde, hydrogen cyanide, hydrogen sulfide, methanol, methyl ethyl ketone, methylene chloride, oxides of nitrogen such as nitrogen oxide, propylene, styrene, oxides of sulfur such as sulfur dioxide, toluene, vinyl chloride, arsenic, cadmium, chlorine, 1,2-dibromochloropropane (DBCP), iron, lead, phosphate, radon, selenium, or uranium. The adsorbent and/or catalyst binder system of this invention can remediate individual contaminants or multiple contaminants from a single source. This invention achieves improved efficiency by adsorbing a higher amount of contaminants and by reducing the contamination level to a much lower value than by non-enhanced particles.
In yet another aspect, the invention provides a method for catalyzing the degradation of an organic compound comprising contacting the organic compound with the adsorbent and/or catalyst system for a sufficient time to catalyze the degradation of an organic compound. In one embodiment, the catalysis reaction is at room temperature. In a one embodiment, the organic compound is a chlorinated organic compound, such as trichloroethylene (TCE). In one embodiment, the catalyst and binder system catalyzes the hydrolysis of the chlorinated organic compounds.
In yet another aspect, the invention provides a method for reducing or eliminating the amount of a contaminant from a gas stream by catalysis comprising contacting the adsorbent and/or catalyst binder system with a gas stream containing a contaminant comprising an oxide of nitrogen, an oxide of sulfur, carbon monoxide, hydrogen sulfide, or mixtures thereof for a sufficient time to reduce or eliminate the contaminant amount. In one embodiment, the catalysis reaction is at room temperature.
For environmental remediation applications, adsorbent and/or catalyst particles of the invention are typically placed in a container, such as a filtration unit. The contaminated stream enters the container at one end, contacts the particles within the container, and the purified stream exits through another end of the container. The particles contact the contaminants within the stream and bond to and remove the contamination from the stream. Typically, the particles become saturated with contaminants over a period of time, and the particles must be removed from the container and replaced with fresh particles. The contaminant stream can be a gas stream or liquid stream, such as an aqueous stream. The particles can be used to remediate, for example, waste water, production facility effluent, smoke stack gas, auto exhaust, drinking water, and the like.
The particle/binder system of the invention can be used preferably as the adsorbent or catalytic medium itself. In an alternate embodiment, the system is used as an adsorbent or catalytic support.
When the particle adsorbs a contaminent, the particle of this invention bonds with the contaminant so that the particle and contaminant are tightly bound. This bonding makes it difficult to remove the contaminant from the particle, allowing the waste to be disposed of into any public landfill. Measurements of contaminants adsorbed on the particles of this invention using an EPA Toxicity Characteristic Leachability Procedure (TCLP) test known to those of skill in the art showed that there was a very strong interaction between the particles of this invention and the contaminants such that the contaminant is held very tightly.
Although the particle system bonds tightly to the contaminent, the system of the invention can be regenerated by various techniques, such as by roasting it in air to reoxidize the particles.
In one embodiment, component b comprises aluminum oxide, copper oxide, and manganese dioxide. In this embodiment, the binder is preferably colloidal alumina. In this embodiment, the acid is preferably acetic acid. In this embodiment, the binder is from 1 to 99.9 parts by weight, preferably from 5 to 35 parts by weight, the aluminum oxide is from 1 to 99.9 parts by weight, preferably from 55 to 85 parts by weight, the copper oxide is from 1 to 99.9 parts by weight, preferably from 1 to 20 parts by weight, and the manganese oxide is from 1 to 99.9 parts by weight, preferably from 1 to 20 parts by weight. In another embodiment, the binder is 20 parts by weight, aluminum oxide is 70 parts by weight, copper oxide is 5 parts by weight, and manganese dioxide is 5 parts by weight.
In another embodiment, component b comprises aluminum oxide and activated carbon. In this embodiment, the binder is preferably colloidal alumina. In this embodiment, the acid is preferably acetic acid. In this embodiment, the binder is from 1 to 99.9 parts by weight, preferably from 5 to 35 parts by weight, the aluminum oxide is from 1 to 99.9 parts by weight, preferably from 45 to 75 parts by weight, and the activated carbon is from 1 to 99.9 parts by weight, preferably from 35 to 55 parts by weight. In another embodiment, the binder is 20 parts by weight, aluminum oxide is 60 parts by weight, and activated carbon is 5 parts by weight.
In another embodiment, component b comprises copper oxide and manganese dioxide. In this embodiment, the binder is preferably colloidal alumina. In this embodiment, the acid is preferably acetic acid. In this embodiment, the binder is from 1 to 99.9 parts by weight, preferably from 5 to 35 parts by weight, the copper oxide is from 1 to 99.9 parts by weight, preferably from 35 to 55 parts by weight, and the manganese dioxide is from 1 to 99.9 parts by weight, preferably from 25 to 55 parts by weight. In another embodiment, the binder is 20 parts by weight, copper oxide is 40 parts by weight, and manganese dioxide is 40 parts by weight.
In another embodiment, component b comprises aluminum oxide, copper oxide, manganese dioxide and activated carbon. In this embodiment, the binder is preferably colloidal alumina. In this embodiment, the acid is preferably acetic acid. In this embodiment, the binder is from 1 to 99.9 parts by weight, preferably from 5 to 35 parts by weight, the aluminum oxide is from 1 to 99.9 parts by weight, preferably from 45 to 75 parts by weight, the copper oxide is from 1 to 99.9 parts by weight, preferably from 1 to 20 parts by weight, the manganese dioxide is from 1 to 99.9 parts by weight, preferably from 1 to 20 parts by weight, and activated carbon is from 1 to 99.9 parts by weight, preferably from 1 to 25 parts by weight. In another embodiment, the binder is 19.9 parts by weight, aluminum oxide is 60 parts by weight, copper oxide is 5.98 parts by weight, manganese dioxide is 4.98 parts by weight, and activated carbon is 9.95 parts by weight.
In another embodiment, the component b comprises aluminum oxide, silicon dioxide and activated carbon. In a further embodiment, the particle comprises 1-99 parts, preferably 5-35 parts, more preferably 20 parts by weight aluminum oxide, 1-99 parts, preferably 5-35 parts, more preferably 20 parts by weight silicon dioxide and 1-99 parts, preferably 25-55 parts, more preferably 40 parts by weight activated carbon. In this embodiment, the binder is preferably colloidal alumina and the acid is preferably acetic acid. The binder is from 1 to 99.9 parts by weight, preferably from 5 to 35 parts by weight
In another embodiment, the catalyst and binder system can be used as an oxidation catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of V2O5, WO2, WO3, TiO2, Re2O7, As2O3, As2O5, OSO4, or Sb2O3. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and V2O5, WO2, WO3, TiO2, Re2O7, AS2O3, AS2O5, OsO4, or Sb2O3 are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a Lewis acid catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of V2O5, ZrO2, TiO2, MgO, ThO2 or lanthanide oxides. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and V2O5, ZrO2, TiO2, MgO, ThO2 or lanthanide oxides are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a cracking catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of CuO, ZnO, Ag2O, AgO, CdO, SnO2, PbO, V2O5, ZrO2, MgO, ThO2 or lanthanide oxides. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and CuO, ZnO, Ag2O, AgO, CdO, SnO2, PbO, V2O5, ZrO2, MgO, ThO2 or lanthanide oxides are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a reduction catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of MnO2, Fe2O3, Fe3O4, RU2O3, OsO4, CoO, Co2O3, RuO or NiO. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and MnO2, Fe2O3, Fe3O4, RU2O3, OsO4, CoO, Co2O3, RuO or NiO are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a coal gasification catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of Fe2O3, Fe3O4, CoO or Co2O3. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and Fe2O3, Fe3O4, CoO, or Co2O3, are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a coal gas reforming catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of Fe2O3, Fe3O4, CoO or Co2O3. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and Fe2O3, Fe3O4, CoO, or Co2O3, are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a hydrogenation catalyst. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of Fe2O3, Fe3O4, CoO or Co2O3. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and Fe2O3, Fe304, CoO or Co2O3 are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a desiccant. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide of zeolite, MgO, or ThO2. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and zeolite, MgO, or ThO2 are each from 1 to 90 parts by weight.
In another embodiment, the catalyst and binder system can be used as a catalyst support. In one embodiment, the system comprises colloidal alumina as a binder, Al2O3, and one or more of the following oxide particles of MgO or ThO2. In another embodiment, the colloidal alumina is from 10 to 30 parts by weight, Al2O3 is from 1 to 90 parts by weight, and MgO or ThO2 are each from 1 to 90 parts by weight.
In another embodiment, the invention relates to a composition for binding adsorbent and/or catalytic particles to produce an agglomerated particle comprising (a) a colloidal metal oxide or colloidal metalloid oxide and (b) an acid. In this composition, in one embodiment, the colloidal metal oxide or colloidal metalloid oxide comprises colloidal alumina or colloidal silica. In this composition, in one embodiment, the acid is acetic acid or nitric acid.
In another embodiment, the invention relates to a method for binding adsorbent and/or catalytic particles, comprising the steps of:
(a) mixing colloidal alumina or colloidal silica with the particles and an acid;
(b) agitating the mixture to homogeneity; and
(c) heating the mixture for a sufficient time to cause cross-linking of the aluminum oxide in the mixture.
In one embodiment, the colloidal alumina or colloidal silica is colloidal alumina. In another embodiment, the colloidal alumina is from 20% to 99% by weight of the mixture. In another embodiment, the acid is nitric acid.
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds claimed herein are made and evaluated, and are intended to be purely exemplary of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in xc2x0 C. or is at room temperature and pressure is at or near atmospheric.